1. Field of the Invention
The present invention relates to a karaoke system capable of scoring singing of a singer on accompaniment thereof, in which a compact disk or a laser disk is used for the accompaniment.
2. Description of the Prior Art
In a conventional karaoke system, a voice, or a singing sound of a singer is inputted through a microphone and then transformed into a voice signal. This voice signal is inputted into and then amplified in an amplifier. The amplified voice signal is filtered through a low pass filter and then outputted through speakers. At the same time, an audio signal accompanied with the singing of the singer is outputted through the speakers from an audio system of the karaoke system.
FIG. 1 is a block diagram of a conventional karaoke system showing a process of scoring the singing of a singer on accompaniment thereof.
As shown in FIG. 1, in the conventional system, the voice of the singer is inputted through the microphone, which is not shown, and is transformed into a voice signal VO and then is outputted to a low pass filter 1 by the microphone. A low pass filter 1 low-pass filters voice signal VO so as to eliminate noise signals therefrom, and then outputs a low pass filter signal LV. Low pass filter signal LV is inputted into speakers and a first level detector 2. First level detector 2 detects a signal level of low pass filter signal LV and outputs a first level detection signal LD1.
Meanwhile, an audio signal AU including a voice signal of a professional singer or an accompaniment signal generated from an audio device, which is not shown, of the karaoke system is outputted into the speakers and a second level detector 3, and second level detector 3 detects a level of audio signal AU to generate a second level detection signal LD2. First and second level detectors 2 and 3 are synchronized with each other according to a sync signal LS of a sync signal generator 4, and then first level detection signal LD1 from first level detector 2 and second level detection signal LD2 from second level detector 3 are synchronized with each other and then inputted into a microprocessor 5.
Microprocessor 5 computes level differences between signals LD1 and LD2, and stores up the level differences in a memory 6 until the singing of the singer is finished. After the singing is finished, the microprocessor sums up all the level differences, and outputs a score calculated on the basis of the level differences to a score display device which is not shown. In this case, it goes without saying that the less the sum of the level differences is, the higher the score is.
However, in the conventional karaoke system capable of scoring the singing of the singer on accompaniment thereby as shown in FIG. 1, since the score of the singing of the singer is calculated on the basis of only the level difference, which is a difference of energy between the signals inputted in the microprocessor, other factors such as a tempo, a tone, etc., of the singing of the singer are not taken into consideration. In other words, when the level of the singing of the singer is similar to that of the audio signal, the score is estimated to be high.
Accordingly, there has been a disadvantage in that a reliability has not been given to the scoring by the conventional karaoke system.